Application of inverse finite element method in tube hydroforming modeling

In tube hydroforming, the inverse finite element method (IFEM) has been used for estimating the initial length of tube, axial feeding and fluid pressure. The already developed IFEM algorithm used in this work is based on the total deformation theory of plasticity. Although the nature of tube hydroforming is three-dimensional deformation, in this paper a modeling technique has been used to perform the computations in two-dimensional space. Therefore, compared with conventional forward finite element methods, the present computations are quite fast with no trial and error process. In addition, the solution provides all the components of strain. Using the forming limit diagram (FLD), the components of strain can lead us to measure the potentials for failures or wrinkles during the deformation. The results of analysis for free bulging and square bulging have been compared with some published experimental data and the results obtained by conventional commercial software.